1,2-Wittig rearrangement

A 1,2-Wittig rearrangement is a organic reaction and a 1,2-rearrangement of an ether with an alkyllithium compound.

Related Topics:
Organic reaction - 1,2-rearrangement - Ether - Alkyllithium

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:mathrm{R_1R_2CH0R_3 + R_4Li ightarrow R_1R_2R_3CH0^-Li^+ + R_4H}

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The intermediate product is a alkoxy lithium salt and the final product a alcohol. When R2 is a good leaving group and electron withdrawing functional group such as a cyanide (CN) group, this group is eliminated and the corresponding ketone is formed.

Related Topics:
Alcohol - Functional group - Cyanide - Ketone

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:mathrm{R_1(CN)CH0R_3 + R_4Li ightarrow R_1R_3C=O + LiCN + R_4H}

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The reaction mechanism centers around the formation of a free radical pair with lithium migrating from the carbon atom to the oxygen atom. The R3 radical then recombines.

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:mathrm{R_1R_2CLi0^o + R_3^o ightarrow R_1R_2C^o0Li + R_3^o}

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